Recently, tea beverages, which are natural, healthy, instant and convenient, enjoy quickly increased popularity at home and abroad, and become the most promising and potential beverages. However, most of tea beverages in the current market of China are those containing sugar and flavoring agents, which change the purely natural flavors of tea leaves and do not really reflect the natural and healthy characteristics of tea leaves. Although pure tea beverages reflect the natural and healthy characteristics of tea leaves, the current pure tea beverages in market more or less have the following problems due to the current processing devices and processing procedures.                1. The extraction process of tea leaves generally refers to hot extraction, and as the extraction temperature and time increase, the tea soup (in particular, green tea and scented tea (based on green tea)) turns dark easily and has a stewed flavor and taste, and therefore the quality of the extraction liquid of tea leaves can hardly be guaranteed and the flavor of the tea soup begins to deteriorate during extraction.        2. During the process of sterilization, ultra high temperature short time sterilization technique has been widely applied. In order to reduce oxidization of tea polyphenols and alteration of flavor ingredients at high temperature, the tea soup is generally subjected to the degassing treatment (such as under vacuum) before sterilization. However, the degassing treatment per se would cause a great loss of fragrant substances in the tea soup and result in insufficient fragrance of the tea beverages.        3. As for filling processes, aseptic cold filling is not widely applied yet, and hot filling is the dominant filling. Since hot filling is carried out at a relatively high temperature, the flavor of the tea soup is further deteriorated.        4. During storage, color browning is serious, fragrance is dull, and taste intensity and fresh feeling reduce in tea beverages.        
As to the above-mentioned problems, people have been looking for the solutions and techniques for solving them all the time. For example, the employment of low-temperature extraction can reduce the oxidization of tea polyphenols to some extent as compared to hot extraction. However, low-temperature extraction (≦40° C.) has a low extraction efficiency and takes a long time, and therefore cannot meet the requirement of large-scale production of tea beverages obviously. In order to solve the problem of color browning in tea soup, some antioxidants are generally used, however, they may result in impure taste of the tea soup and loss of the natural flavor of tea leaves.